1. Field of the Invention
This invention is an instant electrically powered heating system for providing a rapid warm-up to the passenger compartment of a motor vehicle or the like. The heating level may be adjusted and the heating coils are automatically turned off after a manually adjustable time period.
2. Description of the Prior Art
In conventional heaters for motor vehicles, ambient and/or outside air is passed through a heat exchanger and forced into the passenger compartment by a fan through one or more vents generally located in or near the wall separating the passenger compartment from the engine. The heat exchanger also receives fluid from the engine which does not become warm for a significant time after the engine is started, especially in cold weather. Even when the heater begins to pass warmed air, this air does not directly warm the driver, generally because of the location of the heating vents.
Conventional prior art attempts to provide rapid heating to the passenger compartment of the vehicle when the engine is not operating, or prior to warm-up of a cold engine, generally use bulky and often expensive heaters which are also noisy and can drain considerable energy from the vehicle battery, and are thus limited in utility. Furthermore, since heat from the conventional heater is slow in starting, the driver when entering a motor vehicle in cold weather encounters a cold environment, and is uncomfortable until after the engine warms and provides sufficient warm air to the passenger compartment. This situation is unsafe, and could be the cause of accidents. A fast acting heater which is electrically powered, which may be mounted wherever desired and which may be positioned to supply warm air immediately to the driver would be a desirable addition to a motor vehicle.
Some prior art auxiliary electrically powered heaters attempt to overcome the power drain problem by using the three phase AC voltage from the vehicle alternator, but such units are generally complex and expensive. Others attempt to prevent excessive power drain and/or burn-out of the auxiliary heater by using complex or expensive heat or current sensing devices to turn off the auxiliary heater when the vehicle heat supply is sufficient. Representative prior art is shown in U.S. Pat. Nos. 3,313,915; 4,004,126; 4,034,204; 4,188,527; 4,232,211 and 4,562,957.
The present invention avoids the disadvantages of the prior art by providing a small, inexpensive auxiliary electrically powered instant heating system constructed from standard components. The unit may be mounted under the dashboard to supply heat where it is most needed. The heat and power levels are variable, and the electrical power to the heating coils is automatically turned off after a manually adjustable time delay.